ACSS2 and Iron deficiency anemia: Compared with the other three groups (αCSα/–SEA, -α3.7/–SEA, -α4.2/–SEA), the group SEA had a significant lower serum ferritin levels (P < 0.001, respectively), this may be due to patients with SEA genetype generally do not receive blood transfusion therapy frequently unless combined with iron deficiency anemia, vitaminD deficiency, infection caused by long-term malnutrition anemia.